Quick Question: Normalizing DRVVT Ratio Results

For our October, 2018 Quick Question we asked, “For lupus anticoagulant testing, how do you express the DRVVT screen and confirm results?” Here are the answers from 36 respondents: a. Ratio of screen to confirm: 17 = 47% b. Ratio of screen to confirm normalized to MRI: 17 = 47% c. Difference of screen and […]

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Quick Question Archive

Oct 8 2018

george

More on Weight-based Aspirin Dosing

Thanks to my friend and colleague Gordon Ens, Inflammatory Markers Laboratory, for the heads-up on this August 31, 2018 Cleveland HeartLab article, Aspirin for the Heart, One Dose Doesn’t Fit All (click or tap) This is in follow-up to our August 13 post, Weight-based Aspirin Dosing, featuring Santosh Kadel at the University of Texas Medical […]

Antiplatelet Therapy

Quick Question: DRVVT Results

The International Society on Thrombosis and Haemostasis and the Clinical and Laboratory Standards Institute agree that the lupus anticoagulant (LAC) test profile should employ two testing platforms, and both recommend, among other choices, an assay based upon the dilute Russell viper venom time (DRVVT) and a second assay based on the PTT. Each platform employs […]

Thrombophilia

Platelet Neutralization Procedure

Geoffrey Wool, MD, PhD, Associate Director of Coagulation at the University of Chicago Medical Center Laboratory, provided an excellent Webinar, “Lupus Anticoagulant Testing: Managing Interferences and Optimizing Quality” on the Labroots provider site. Dr. Wool addresses among other issues the time-honored platelet neutralization procedure (PNP), in which concentrated phospholipid extracted from platelets is used to […]

Mixing Studies

An Athletic 59-YO Male with a DVT

Here is one of our April 22, 2018 Medical Laboratory Professionals Week case studies for your response. Watch for more “Lab Week” case studies in the weeks ahead! I (George) have corresponded with a gentleman since 2009; we’ve developed an electronic friendship, though we’ve never met F2F. “John” first contacted me in 2009, a year […]

Thrombophilia

Protein S Activity < 1%

George had a phone conversation with a reference lab colleague who generated protein S levels on a patient specimen: free and total protein S concentrations over 70%, clot-based protein S activity less than 1%. PT normal, PTT prolonged by about 15 seconds. DRVVT prolonged, not shortened by platelet phospholipid-rich reagent. What could account for these […]

Thrombophilia

D-dimer Controls

In 2008, John Olson, MD provided a lengthy comment on the variabilities of D-dimer assay results, and since then a look-back reveals the number of discussions we’ve held about the variability in D-dimer reporting and how this affects clinical decision making. In the years since Dr. Olson’s post little has been accomplished to harmonize D-dimer […]

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Quick Question Archive

Jan 11 2018

george

Age-adjusted D-dimer, 12/2017 CAP Today

The December CAP Today featured an article about age-adjusted D-dimer assay reference intervals.The article features interviews with Drs. Russell Higgins, Dorothy Adcock, Karen Moser, Oksana Volod, and Chris Lehman. See also our in-depth on this topic in response to a November 8, 2014 entry from Sylvia Stacy, Concord Hospital, NH. It appears from the CAP […]

Thrombophilia

November Quick Question: Thrombophilia

Here are the results of our November, 2017 Quick Question, answered by 60 respondents: Question: When should you perform an antithrombin, protein C, and protein S profile? a. Soon after starting anticoagulant therapy: chosen by 0 respondents, 0% b. Just after a thrombotic event but before starting anticoagulant: chosen by 10 respondents, 17% c. Seven […]

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Quick Question Archive

Nov 2 2017

george

When to Collect Thrombophilia Specimens

George has been communicating with Drs. Elaine Keohane (Rutgers) and Larry Smith (Abbott) about how long to wait after a thrombotic event to collect a specimen for a thrombosis risk profile. Thrombosis risk profiles include assays for antithrombin, protein C, and protein S deficiencies, which can’t be accurately measured during periods of acute inflammation (such […]

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Anticoagulant Therapy

Thrombophilia

Quick Question: Normalizing DRVVT Ratio Results

More on Weight-based Aspirin Dosing

Quick Question: DRVVT Results

Platelet Neutralization Procedure

An Athletic 59-YO Male with a DVT

Protein S Activity < 1%

D-dimer Controls

Age-adjusted D-dimer, 12/2017 CAP Today

November Quick Question: Thrombophilia

When to Collect Thrombophilia Specimens

George Fritsma MS MLS

Cheat Sheets from George

Questions or Comments?

Quick Question